Evolution and Structural Basis of Curcuminoid and Gingerol Formation in Turmeric and Ginger

植物代谢中的两个重要问题是：导致植物产生大量化合物的机制是什么？这些机制是如何进化的？生姜和姜黄含有大量结构相似的化合物，似乎是由相同的生化途径产生的。这些化合物，包括姜黄素、其他二芳基庚烷类化合物、姜辣素和姜辣素样化合物，由聚酮化合物脱氢酶样酶（PKS）产生。由于这两个物种产生如此大量的相关化合物，因此它们是用于研究植物中产生此类化合物的差异的分子和结构基础的理想系统。选择这些化合物作为该项目的重点，因为它们对植物防御、植物对环境的适应和人类健康的重要性，并且因为已经在姜和姜黄中鉴定了与已知PKS（如查耳酮合酶）相关但不同的大量基因（迄今为止总共41个），所述PKS在两个物种的组织和发育阶段之间差异表达。该项目将专注于确定该基因家族的哪些特定成员负责生产特定的姜黄素，姜辣素，其他二芳基庚烷类化合物或姜辣素相关化合物。它还将确定生姜或姜黄中单个PKS的生化功能。然后，本项目将确定不同PKS之间差异活性的结构基础。这些信息将解决酶结构的变化如何导致酶功能的差异以及这些变化如何在植物代谢的背景下演变的重要问题。该项目将影响对酶功能进化的理解，特别是关于酶如何开发新功能。这反过来又会影响对导致植物王国复合多样化并最终导致生物圈中植物多样性的因素的理解。该项目还将产生可用于更好地调整目标植物中特定化合物生产的信息，提高生产“设计植物”的能力。本科生和高中教师将与博士后研究员一起参与这项研究。高中教师（由暑期实习支持）将把纯化的PKS蛋白带到教室，然后与学生一起结晶这些蛋白质。这些蛋白质将包括酶的改变形式，这些酶将被产生以探索这类酶的结构和功能问题，以及控制容易结晶的蛋白质，以便学生们获得成功的经验。因此，高中教师和他们的学生将直接从事一项研究项目，该项目将对酶功能有潜在的重要发现，他们将在此过程中学习结构生物学。

Two large and important questions in plant metabolism are: what are the mechanisms that lead to the large array of compounds produced by plants and how do these mechanisms evolve? Ginger and turmeric contain a large array of compounds that are similar in structure and that appear to be produced by the same biochemical pathway. These compounds, including curcumin, other diarylheptanoids, gingerols and gingerol-like compounds, are produced by polyketide synthase-like enzymes (PKSs). Because these two species produce such a large array of related compounds, they are an ideal system to use to study the molecular and structural basis for differences in production of such compounds in plants. These compounds were chosen as the focus of this project because of their importance to plant defense, to plants' adaptation to the environment, and to human health, and because a large set of genes (41 in total so far) have been identified in ginger and turmeric related to but distinct from known PKSs (such as chalcone synthase) that are expressed differentially between tissues and developmental stages of the two species. This project will focus on identifying which specific members of this gene family are responsible for production of specific curcuminoids, gingerols, other diarylheptanoids or gingerol-related compounds. It will also determine the biochemical function of individual PKSs in ginger or turmeric. This project will then determine the structural basis for differential activity among the different PKSs. This information will address the important questions of how changes in enzyme structure lead to differences in enzyme function and how these changes evolve in the context of plant metabolism. Broader Impacts This project will impact understanding of the evolution of enzyme function, especially with regard to how enzymes develop new functions. This in turn will impact understanding of factors that lead to compound diversification in the plant kingdom and ultimately to plant diversity in the biosphere. This project will also produce information that could be used to better tailor the production of specific compounds in target plants, increasing the ability to produce "designer plants". Undergraduate students and high school teachers will work with post-doctoral fellows in this research. The high school teachers (supported by summer internships) will take purified PKS proteins to their classrooms and then will work with their students to crystallize these proteins. These proteins will include altered forms of the enzymes, which will be produced to probe the questions of structure and function in this enzyme class, as well as control proteins that easily crystallize, so that the students will have a successful experience. Thus, the high school teachers and their students will work directly on a research project that will have potentially important findings regarding enzyme function, and they will learn about structural biology in the process.